Eosinophilic Leukemia: a Morphologic and Histochemical Study.

I N SPITE of the rarity of eosinophilic leukemia, many investigators have reported a number of morphologic alterations of the eos nophils present in the blood and/or bone marrow of patients with eosinophilic leukemia.6’1 ‘ 13.1 6, 18, 19,21 ,24,26,293 I ,34,36,39,40,42,45,4753 The cytologic alterations have included a sparcity of eosinophilic granulation in the mature eosinophils, asynchronous nuclear-cytoplasmic maturation and vacuolated cytoplasm. In some instances the eosinophils have a tendency to be larger than normal, to have larger, coarser eosinophilic granules and to exhibit hypersegmentation. In view of the apparent lack of correlated morphologic and histochemical studies of the unusual cells of eosinophilic leukemia, it is the purpose of this report to illustrate and characterize many of the bizarre and unusual morphologic and histochemical features exhibited by the leukemic eosinophils from an individual with terminal acute eosinophilic leukmeia.